One area of the body which is highly prone to chronic pain and degeneration of normal function is the hip joint. Whether caused by disease, aging, overuse, or injury, a significant portion of the population suffers from ailments relating to the hip. An often utilized last resort solution to problems pertaining to the hip joint is total hip replacement (“THR”) surgery. Generally, THR surgery consists of the replacement of the existing ball and socket of the hip joint with prosthetic replacements. The head of the femur (i.e.—the ball) is typically removed and replaced with a femoral component made of biocompatible material, which mirrors the structure of the original bone. The acetabulum (i.e.—the socket) is typically reamed and fitted with a prosthetic acetabular cup component that corresponds and cooperates with the femoral component. This prosthetic acetabular cup component often times includes an outer shell constructed of a metallic material and an insert constructed of plastic, ceramic or metal received within the outer shell. In many cases, the acetabular cup component is anchored in the bone through the use of cements and/or bone growth technology that allows for bone to grow in and around the cup. Such surgery is widely utilized and often highly successful in relieving many problems associated with the hip joint.
Regardless of the high success rate of THR surgeries, even initially successful hip replacements may require revision over time. Most often, where, injury, disease, infection, or the like may bring upon the failure. In revision surgeries, it is necessary to remove the acetabular component previously implanted in the acetabulum. As mentioned above, these components may have been cemented in place or otherwise held by bone or fibrous tissue that may have grown in and around the component. Thus, their removal requires the cutting or chipping away of cement or bone material.
Prior art devices have been proposed that attempt to lessen the difficultly associated with the removal of an acetabular component. Typically, these devices include a cutting portion and a manipulation portion that requires manual operation by the surgeon. The manipulation portion and the cutting portion are generally configured with respect to each other so as to guide the cutting portion in and around the outer surface of the acetabular cup. While these prior art devices provide a guide for cutting that may indeed aid in the removal of the acetabular cup portion, they require manual operation and significant time to complete the removal step. For example, prior art curved osteotomes, and U.S. Pat. Nos. 5,803,215 and 6,565,575 relate to manual acetabular cup removal instruments. However, it is advantageous to reduce removal time by using a power driven tool.
Therefore, there exists a need for an apparatus capable of removing an acetabular cup from the acetabulum during a revision THR surgery in a fast, easy and reliable fashion without requiring significant exertion on the part of a surgeon.